Calm, collected and usually seemingly indifferent, felines are always the picture of mystery. Even after thousands of years of domestication, cats can be very difficult to read, especially when compared to the wear-it-on-their-paw affection of most dogs.

According to a report from Mother Nature Network, a team of scientists from the University of Lincoln in the U.K. analyzed the expressions of 29 cats in an animal shelter in Canada. The researchers made use of a computer program called Cat Facial Action Coding System (CatFACS), observing the changes in the cats’ expression both with and without humans nearby.

It turns out cats are either angry, afraid or engaged. Angry felines are quite easily identifiable with flat ears. They also tend to hiss or growl. Other behavioral signs are cats licking their noses, dropping their jaws, opening their mouths wide or meowing loudly.

Meanwhile, scared cats — who can be dangerous as well — can be recognized by their excessive blinking or half-blinking. They also tend to tilt their heads and look to the left. Cats in a more relaxed mood exhibit much of the same behavior, except they tilt their head and look to the right side. … read more here